Telephone companies are now beginning to provide distinctive ringing as a feature for its customers. Distinctive ringing is a feature which allows a single telephone line in a home to be assigned more than one telephone number. This is accomplished in the central office of the telephone company, which utilizes computer software to forward a specific ring cadence in response to an assigned telephone number. Thus, if a customer is assigned a "main" telephone number, a "teen line" telephone number and a "private line" telephone number, a different ring cadence is assigned each number. If a caller dials the main telephone number, all of the phones in the customer's home will ring as usual--with a two second "on" and four second "off" cadence. If a caller dials the teen line number, a different cadence is transmitted--for example, eight hundred milliseconds on, four hundred milliseconds off, eight hundred milliseconds on, and four thousand milliseconds off. This would produce two short rings in each set of cadences. If the private line number was dialed, then a short/long/short ring cadence would be transmitted. Thus, a "distinctive" ring is produced for each of the separate telephone numbers assigned to a customer. This allows the customer to know who the call may be intended for prior to answering the telephone. At the same time, the convenience and lower cost of using only a single line is maintained by the customer.
Obviously, such a system can be utilized in business as well, wherein a number of departments may be assigned a different telephone number with their own distinctive ring.
The main problem with the use a distinctive ring system is that every telephone on the line will ring. Thus, while the customer will know to whom the call is generally directed, it will be necessary to listen to the ringing of all of the telephones no matter who the call is directed to. This can become quite annoying.
Another problem is if selective use of a telephone answering device is desired with the phone system. Since conventional telephone answering machines are activated by the ringing of the telephone, some of these machines cannot discriminate between the various distinctive ring cadences which occur on the line. Thus, the machine will answer the phone no matter which cadence is transmitted to the customer. Many times it is desirable that only one of several lines be answered with the telephone answering machine. For example, it may be desired that the main telephone number be answered by the answering machine while the customer desires to personally respond to any telephone calls on a private line. It is not possible to utilize conventional answering machines in this fashion on a distinctive ring telephone system.
It is therefore a general object of the present invention to provide a convertor apparatus for converting a distinctive ring into a selective ring telephone system.
Another object is to provide a convertor apparatus which is connected at the customer's premises to the conventional existing telephone lines to convert the signal into a selective ring feature.
A further object is to provide a convertor apparatus which will ring only selected phones based upon the distinct cadence transmitted over the main telephone line.
Still another object is to provide a convertor apparatus which will ring selected telephones yet permit speech-carrying current to all telephones.
These and other objects will be apparent to those skilled in the art.